Human type V adenylyl cyclase

ABSTRACT

A DNA sequence encoding a human adenylyl cyclase is described. The amino acid sequence of the adenylyl cyclase is also described.

FIELD OF THE INVENTION

[0001] This invention relates to DNA encoding a human adenylyl cyclase. This invention also relates to the adenylyl cyclase encoded by that DNA. Referred to herein as the human type V adenylyl cyclase (hAC5) polypeptide, this enzyme can be used as a tool to screen for agonists and antagonists that can either stimulate or inhibit type V adenylyl cyclase activity Such compounds have therapeutic utility in treating (1) diseases that are caused by aberrant activity of this enzyme and (2) diseases whose symptoms can be ameliorated by stimulating or inhibiting the activity of type V adenylyl cyclase.

[0002] The present invention also relates to the isolated entire human gene encoding the human type V adenylyl cyclase, methods for the recombinant production of purified human type V adenylyl cyclase and the proteins made by these methods, antibodies against the whole human type V adenylyl cyclase or regions thereof, vectors, nucleotide probes, and host cells transformed by genes encoding polypeptides having human type V adenylyl cyclase activity, along with diagnostic and therapeutic uses for these various reagents.

BACKGROUND OF THE INVENTION

[0003] Adenylyl cyclases direct the intracellular synthesis of the primary second messenger, cyclic-3′,5′-adenosine monophosphate (cAMP), by converting ATP to cAMP, principally in response to a diverse family of membrane spanning, G-protein coupled receptors, each activated by its own extracellular hormone or protease. Signal transduction for G-protein coupled receptors occurs through a coupled heterotrimeric G protein complex composed of the alpha (G_(a)), and beta/gamma (G_(bg)) subunits. Upon receptor stimulation, G_(a) exchanges GTP for GDP, dissociates from both G_(bg) and the receptor, and proceeds to directly regulate various effectors, including adenylyl cyclase. Multiple families of G_(a) proteins have been identified, two of which are named for their effects on regulating adenylyl cyclase activity (G_(as) family stimulates all adenylyl cyclases, while G_(ai) family inhibits most but not all of the adenylyl cyclases). Each of these G_(a) proteins has its own tissue distribution, and subset of coupled receptors, which favors receptor specific regulation of adenylyl cyclase.

[0004] Additional studies have suggested other means by which adenylyl cyclase activity may be regulated within tissues. This concept is derived from findings that a number of adenylyl cyclase isoforms exist, each with their own gene locus, distinct set of responses to intracellular signals and unique tissue distribution. To date, nine separate isoforms (Types I-IX) have been characterized, principally from rodents, each with its own regulatory properties and tissue specific distribution.

[0005] The structure of adenylyl cyclases has been greatly studied and the putative domains given standard nomenclature. Topographically, the adenylyl cyclase isoforms are similar, having two six-transmembrane spanning regions associated with an intracellular N-terminus, a large cytoplasmic loop (ICD III, more commonly referred to as “C₁”) and an intracellular C-terminus (more commonly referred to as “C₂”). The transmembrane region between the N-terminus and the C₁ loop is commonly referred to as “M1”. The M1 region has three extracellular domains (ECD I, II and III), two intracellular domains (ICD I and II) and six transmembrane domains (TM I, II, III, IV, V and VI). The region between the C₁ loop and the C-terminus is referred to as “M2”. The M2 region has three extracellular domains (ECD IV, V and VI), two intracellular domains (ICD IV and V) and six transmembrane domains (TM VII, VIII, IX, X, XI and XII). The N-terminus is commonly divided into two regions, designated “N₁” and “N₂”. The large C₁ cytoplasmic loop is also divided into two regions, a long “C_(1a)” region and a shorter “C_(1b)” region. Lastly, the C-terminus is divided into a long “C_(2a)” region and a shorter “C_(2b)” region. An extensive discussion of these regions can be found in Broach, et al., WO 95/30012, which is incorporated herein by reference. The amino acid sequence of the C_(1a) and C_(2a) regions are conserved among the different isoforms. On the other hand, the N-terminus, C_(1b) and C_(2b) regions show the most diversity among the various isoforms.

[0006] Based on sequence and functional similarities, these isoforms fall into six distinct classes of adenylyl cyclases. Type V is in the same class as type VI, showing sequence similarity even in the transmembrane regions where the greatest level of divergence is noted among the isoforms. Type V is expressed predominantly in heart and brain tissue. Type VI has a somewhat broader distribution but its dominant expression is also in heart and brain tissue. Type V, like type VI, has a relatively longer N-terminus and relatively shorter C-terminus, lacking the C_(2b) region, than the other isoforms.

[0007] Diversity in activities, and differences in distribution and prevalence of adenylyl cyclase isoforms, may contribute to tissue specific regulation of cAMP levels. It is expected that by taking advantage of distinct structural and biochemical differences between different adenylyl cyclases, isoform specific or selective modulators can be discovered. This, in conjunction with knowledge of the proportion and distribution of each isoform in select tissues provides a means by which one can develop either tissue specific, or selective pharmacological agents since it is expected that isoform specific modulators would have tissue specificity related to the distribution of that isoform.

[0008] Key to the development of selective pharmacological agents is information pertaining to the tissue specific distribution and prevalence of each isoform. To date most of this information is available for isoform mRNA levels in a handful of non-human mammals, although some select mRNA (e.g. Type V) have been measured for many human tissues. Acquiring information on protein isoform distribution in human tissues is considered an important aspect of pharmaceutical research in this area, since this could either strengthen existing target information or point to different isoforms, when compared with mRNA data

[0009] To date, only three full length human adenylyl cyclase isoforms have been cloned: Type II adenylyl cyclase (Stengel, et al., Hum. Genet. 90:126-130 (1992)), Type VII adenylyl cyclase (Nomura, et al., DNA Research 1:27-35 (1994)) and Type VIII adenylyl cyclase (Defer, et al., FEBS Letters 351:109-113 (1994)).

[0010] Type V has been cloned from canine heart (Ishikawa, et al. Jour. Biol. Chem. 267(19):13553-13557 (1992) and Ishikawa, WO 93/05061). The human isoform has not been cloned until now.

SUMMARY OF THE INVENTION

[0011] One aspect of the invention is an isolated and purified human type V adenylyl cyclase (hAC5) polypeptide comprising the amino acid sequence of FIG. 1 (SEQ ID NO:2).

[0012] Another aspect of the invention is an isolated and purified nucleic acid encoding for the hAC5 polypeptide.

[0013] Yet another aspect of the invention is an isolated and purified nucleic acid comprising the nucleotide sequence of FIG. 1 (SEQ ID NO:1), which encodes a biologically active hAC5 polypeptide, or fragment thereof

[0014] Still another aspect of the invention is an isolated and purified nucleic acid comprising the nucleotide sequence of FIG. 1 (SEQ ID NO:1), which encodes a biologically active soluble hAC5 peptide fragment.

[0015] Another aspect of the present invention also relates to the human gene encoding human type V adenylyl cyclase, which has both diagnostic and therapeutic uses as are described below. Included within this invention are proteins or peptides having substantial homology with proteins or peptides comprising the amino acid sequence of FIG. 1 or encoded by a gene having substantial homology with the nucleotide sequence of FIG. 1, and which exhibit the same characteristics of human type V adenylyl cyclase.

[0016] Yet another aspect of the invention is a method of producing hAC5 which comprises incorporating a nucleic acid having the nucleotide sequence of FIG. 1 (SEQ ID NO:1) into an expression vector, transforming a host cell with the vector and culturing the transformed host cell under conditions which result in expression of the gene.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1(A-H) is the DNA (SEQ ID NO:1) and deduced amino acid sequence (SEQ ID NO:2) of human type V adenylyl cyclase. The entire coding sequence, as well as portions of the 5′ and 3′ untranslated sequences, are shown. The whole sequence was done bidirectionally twice by dideoxy sequencing method using Taq polymerase.

DETAILED DESCRIPTION OF THE INVENTION Definitions

[0018] Before proceeding further with a description of the specific embodiments of the present invention, a number of terms will be defined:

[0019] The terms “substantially pure” and “isolated” are used herein to describe a protein that has been separated from the native contaminants or components that naturally accompany it. Typically, a monomeric protein is substantially pure when at least about 60 to 70% of a sample exhibits a single polypeptide backbone. Minor variants or chemical modifications typically share approximately the same polypeptide sequence. A substantially pure protein will typically comprise over about 85 to 90% of a protein sample, preferably will comprise at least about 95%, and more preferably will be over about 99% pure. Purity is typically measured on a polyacrylamide gel, with homogeneity determined by staining. For certain purposes, high resolution will be desired and HPLC or a similar means for purification utilized. However, for most purposes, a simple chromatography column or polyacrylamide gel will be used to determine purity. Whether soluble or membrane bound, the present invention provides for substantially pure preparations. Various methods for their isolation from biological material may be devised, based in part upon the structural and functional descriptions contained herein. In addition, a protein that is chemically synthesized or synthesized in a cellular system that is different from the cell from which it naturally originates, will be substantially pure. The term is also used to describe proteins and nucleic acids that have been synthesized in heterologous mammalian cells, bacterial cells such as E. coli and other prokaryotes.

[0020] As used herein, the terms “hybridization” (hybridizing) and “specificity” (specific for) in the context of nucleotide sequences are used interchangeably. The ability of two nucleotide sequences to hybridize to each other is based upon a degree of complementarity of the two nucleotide sequences, which in turn is based on the fraction of matched complementary nucleotide pairs. The more nucleotides in a given sequence that are complementary to another sequence, the greater the degree of hybridization of one to the other. The degree of hybridization also depends on the conditions of stringency which include temperature, solvent ratios, salt concentrations, and the like. In particular, “selective hybridization” pertains to conditions in which the degree of hybridization of a polynucleotide of the invention to its target would require complete or nearly complete complementarity. The complementarity must be sufficiently high so as to assure that the polynucteotide of the invention will bind specifically to the target relative to binding other nucleic acids present in the hybridization medium. With selective hybridization, complementarity will be 90-100%, preferably 95-100%, more preferably 100%.

[0021] “Stringent conditions” are those that (1) employ low ionic strength and high temperature for washing, for example, 0.015 M NaCl/0.0015. M sodium titrate/0.1% NaDodSO₄ at 50° C., or (2) employ during hybridization a denaturing agent such as formamide, for example, 50% (vol/vol) formamide with 0.1% bovine serum albumin (“BSA”)/0.1% Ficoll/0.1% polyvinylpyrrolidone/50 mM sodium phosphate buffer at pH 6.5 with 750 mM NaCl, 75 mM sodium citrate at 42° C. Another example is use of 50% formamide, 5×0.75 M NaCl and 0.075 M sodium citrate (“SSC”), 50 mM sodium phosphate (pH 6.8), 0.1% sodium pyrophosphate, 5× Denhardt's solution, sonicated salmon sperm DNA (50 mg/ml), 0.1% sodium dodecyl sulfate (“SDS”), and 10% dextran sulfate at 42° C., with washes at 42° C. in 0.2×SSC and 0.1% SDS.

[0022] “Isolated” nucleic acid will be nucleic acid that is identified and separated from contaminant nucleic acid encoding other polypeptides from the source of nucleic acid. The nucleic acid may be labeled for diagnostic and probe purposes, using any label known and described in the art as useful in connection with diagnostic assays.

PREFERRED EMBODIMENTS

[0023] The present invention relates to human type V adenylyl cyclase, which is referred to herein as “hAC5”. FIG. 1 shows the DNA sequence of the clone encoding the hAC5 polypeptide along with the deduced amino acid sequence. As used herein, the terms “hAC5 polypeptide” or “hAC5 enzyme” refer to any adenylyl cyclase sharing a common biological activity with the human type V adenylyl cyclase contained in the clone described in Example 1. This “common biological activity” includes but is not limited to an effector function or cross-reactive antigenicity.

[0024] As indicated above, type V adenylyl cyclase is in the same isoform class as type VI, being expressed mainly in the heart and brain. As with the other known isoforms, type V adenylyl cyclase has a similar putative structure: six extracellular domains; five intracellular domains, four small ones and a large cytoplasmic loop; and intracellular amino and carboxy termini.

[0025] However, type V adenylyl cyclase, like type VI, is distinguishable over other adenylyl cyclase isoforms in that it has a larger N-terminus and a relatively shorter C-terminus as it lacks the C_(2b) region. In the other mammalian isoforms (types I-IV and VI-IX), much of the membrane associated secondary structure is well conserved. Certain portions of the hAC5 polypeptide are similarly conserved.

[0026] The scope of the present invention is not limited to the exact sequence of the hAC5 cDNA set forth in FIG. 1 (SEQ ID NO:1), or the use thereof. The invention contemplates certain modifications to the sequence, including deletions, insertions, and substitutions, such as are well known to those skilled in the art. For example, the invention contemplates replacing one or more codons in the cDNA sequence of FIG. 1, with codons that encode amino acids that are chemically equivalent to the amino acids in the native protein. Chemical equivalency is determined, for example, by one or more of the following characteristics: hydrophobicity or hydrophilicity, charge, size, whether the residue is cyclic or non-cyclic, aromatic or non-aromatic. So, for example, a codon encoding a neutral polar amino acid can be substituted with another codon that encodes a neutral polar residue, with the reasonable expectation of producing a biologically equivalent product.

[0027] Amino acid residues can be generally classified into four groups. Acidic residues are hydrophilic and have a negative charge due to loss of H³⁰ at physiological pH. Basic residues are also hydrophilic but have a positive charge due to association with H⁺ at physiological pH. Neutral nonpolar residues are hydrophobic and are not charged at physiological pH. Neutral polar residues are hydrophilic and are not charged at physiological pH. Amino acid residues can be further classified as cyclic or noncyclic, and aromatic or nonaromatic, self-explanatory classifications with respect to the side chain substituent groups of the residues, and as small or large. The residue is considered small if it contains a total of 4 carbon atoms or less, inclusive of the carboxyl carbon. Small residues are, of course, always nonaromatic.

[0028] Of the naturally occurring amino acids, aspartic acid and glutamic acid are acidic; arginine and lysine are basic and noncyclic; histidine is basic and cyclic; glycine, serine and cysteine are neutral, polar and small; alanine is neutral, nonpolar and small; threonine, asparagine and glutamine are neutral, polar, large and nonaromatic; tyrosine is neutral, polar, large and aromatic; valine, isoleucine, leucine and methionine are neutral, nonpolar, large and nonaromatic; and phenylalanine and tryptophan are neutral, nonpolar, large and aromatic. Proline, although technically neutral, nonpolar, large, cyclic and nonaromatic, is a special case due to its known effects on the secondary conformation of peptide chains, and is not, therefore, included in this defined group.

[0029] There are also commonly encountered amino acids, which are not encoded by the genetic code. These include, by way of example and not limitation: sarcosine, beta-alanine, 2,3-diamino propionic and alpha-aminisobutyric acid which are neutral, nonpolar and small; t-butylalanine, t-butylglycine, N-methylisoleucine, norleucine and cyclohexylalanine which are neutral, nonpolar, large and nonaromatic; ornithine which is basic and noncyclic; cysteic acid which is acidic; citrulline, acetyl lysine, and methionine sulfoxide which are neutral, polar, large and nonaromatic; and phenylglycine, 2-naphthylalanine, β-2-thienylalanine and 1,2,3,4tetrahydroisoquinoline-3-carboxylic acid which are neutral, nonpolar, large and aromatic.

[0030] Ordinarily, the hAC5 polypeptide claimed herein will have an overall amino acid sequence having at least 75% amino acid sequence identity with the hAC5 sequence disclosed in FIG. 1, more preferably at least 80%, even more preferably at least 90%, and most preferably at least 95%. More particularly, the N-terminus, C_(1b) and C_(2b) regions of the hAC5 polypeptide or polypeptide fragment claimed herein, will have an amino acid sequence having at least 90%, and most preferably at least 95% amino acid sequence identity with the hAC5 sequence disclosed in FIG. 1. Identity or homology with a sequence is defined herein as the percentage of amino acid residues in the candidate sequence that are identical with the sequence of the hAC5 polypeptide, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent homology, and not considering any conservative substitutions as part of the sequence identity. N-terminal, C-terminal or internal extensions, deletions, or insertions of the hAC5 sequence shall be construed as affecting homology.

[0031] Thus, the claimed hAC5 polypeptide that is the subject of this invention includes molecules having the hAC5 amino acid sequence; fragments thereof having a consecutive sequence of at least 10, 15, 20, 25, 30 or 40 amino acid residues from the hAC5 sequence of FIG. 1, which exhibits the hAC5 polypeptide characteristics; amino acid sequence variants of the hAC5 sequence of FIG. 1 wherein an amino acid residue has been inserted N- or C-terminal to, or within, (including parallel deletions) the hAC5 sequence or its fragments as defined above; amino acid sequence variants of the hAC5 sequence of FIG. 1 or its fragments as defined above which have been substituted by at least one residue, and which exhibit the hAC5 polypeptide characteristics. Of particular interest are those peptides corresponding to those regions where the hAC5 polypeptide is divergent from types I-IV and VI-IX.

[0032] Human type V adenylyl cyclase polypeptides include those containing predetermined mutations by, e.g., homologous recombination, site-directed or PCR mutagenesis; naturally occurring variants of the hAC5 polypeptide; derivatives of the hAC5 polypeptide or its fragments wherein the hAC5 or its fragments have been covalently modified by substitution, chemical, enzymatic, or other appropriate means with a moiety other than a naturally occurring amino acid (for example a detectable moiety such as an enzyme or radioisotope); glycosylation variants of the hAC5 (insertion of a glycosylation site or deletion of any glycosylation site by deletion, insertion or substitution of appropriate amino acid); and soluble forms of the hAC5 polypeptide or fragments thereof. This invention also includes tagging the hAC5 polypeptide, for example, for use in a diagnostic application. Types and methods of tagging are well known in the art, for example, the use of hexa-histidine tags.

[0033] Several regions of the Type V isoform are highly conserved with the other adenylyl cyclase isoforms. Accordingly, it is believed that most sequence modifications to the highly conserved regions such as the extracellular domains, transmembrane regions and short intracellular domains, including deletions and insertions, and substitutions in particular, are not expected to produce radical changes in the characteristics of the hAC5 polypeptide, distinct from those found with similar changes to other isoforms. However, when it is difficult to predict the exact effect of the sequence modification in advance of making the change, one skilled in the art will appreciate that the effect of any sequence modification will be evaluated by routine screening assays.

[0034] The nomenclature used to describe the peptide compounds of the invention follows the conventional practice where the N-terminal amino group is assumed to be to the left and the carboxy group to the right of each amino acid residue in the peptide. In the formulas representing selected specific embodiments of the present invention, the amino- and carboxy-terminal groups, although often not specifically shown, will be understood to be in the form they would assume at physiological pH values, unless otherwise specified. Thus, the N-terminal H⁺ ₂ and C-terminal O⁻ at physiological pH are understood to be present though not necessarily specified and shown, either in specific examples or in generic formulas. Free functional groups on the side chains of the amino acid residues can also be modified by amidation, acylation or other substitution, which can, for example, change the solubility of the compounds without affecting their activity. All of the compounds of the invention, when an amino acid forms the C-terminus, may be in the form of the pharmaceutically acceptable salts or esters. Salts may be, for example, Na⁺, K⁺, Ca⁺², Mg⁺² and the like; the esters are generally those of alcohols of 1-6 carbons.

[0035] In all of the peptides of the invention, one or more amide linkages (—CO—NH—) may optionally be replaced with another linkage which is an isostere such as —CH₂NH—, —CH₂S—, —CH₂CH₂, —CH═CH—(cis and trans), —COCH₂—, —CH(OH)CH₂— and —CH₂SO—. This replacement can be made by in the art. The following references describe preparation of peptide analogs which include these alternative-linking moieties: Spatola, Yega Data 1(3) “Peptide Backbone Modifications” (general review) (March 1983); Spatola, in “Chemistry and Biochemistry of Amino Acids Peptides and Proteins,” B. Weinstein, eds., Marcel Dekker, New York, p. 267 (1983) (general review); Morley, J. S., Trends Pharm Sci, pp. 463-468 (general review) (1980); Hudson, et al., Int J Pept Prot Res 14:177-185 (—CH₂NH—, —CH₂CH₂—) (1979); Spatola, et al., Life Sci 38:1243-1249 (—CH₂—S) (1986); Hann, J Chem Soc Perkin Trans I 307-314 (—CH—CH—, cis and trans) (1982); Almquist, et al., J Med Chem 23:1392-1398 (—COCH₂—) (1980) ; Jennings-White, et al., Tetrahedron Lett 23:2533 (—COCH₂—) (1982); Szelke, et al., European Application EP 45665 (1982) CA:97:39405 (1982) (—CH(OH)CH₂—); Holladay, et al., Tetrahedron Lett 4:4401-4404 (—C(OH)CH₂—) (1983); and Hruby, Life Sci 31:189-199 (—CH₂—S—) (1982).

[0036] Human type V adenylyl cyclase peptides may be purified using techniques of classical protein chemistry, such as are well known in the art. For example, a lectin affinity chromatography step may be used, followed by a highly specific ligand affinity chromatography procedure that utilizes a ligand conjugated to biotin through the cysteine residues of the ligand. Alternately, the hexa-histidine tagged hAC5 polypeptide may be purified using nickel column chromatography.

[0037] One embodiment of the invention relates to recombinant materials associated with the production of the hAC5 polypeptide. One method of producing hAC5 comprises incorporating a nucleic acid having the nucleotide sequence of FIG. 1 (SEQ ID NO: 1) into an expression vector, transforming a host cell with the vector and culturing the transformed host cell under conditions which result in expression of the gene. Suitable expression vectors include pc3hAC6. Examples of host cells includes bacterial, viral, yeast, insect or mammalian cell lines. A preferred host cell is the human embryonic cell line referred to as “HEK-293”.

[0038] The invention also contemplates the use of transfected cells that can be cultured so as to display or express hAC5 on its surface, thus providing an assay system for the interaction of materials with the native hAC5 where these cells or relevant fragments of hAC5 are used as a screening tool to evaluate the effect of various candidate compounds on hAC5 activity in vivo, as is described below. Another embodiment of the invention relates to recombinant materials associated with the production of soluble hAC5 fragments. These include transfected cells, such as E. coli, that can be cultured so as to express active portions of the hAC5 polypeptide, in particular the C1 and C2 (C-terminus) intracellular loops. These soluble fragments can be purified and reconstituted to obtain enzymatic activity. This has been demonstrated with like domains from other isoforms. See Whisnant, et al., Proc. Natl. Acad. Sci.:93:6621-6625 (1996). Such soluble fragments can also be used as a screening tool to evaluate the effect of various candidate compounds on hAC5 activity. Suitable cells for transfection include bacterial cells, insect cells such as Sf-9 cells, yeast cells and most mammalian cell lines.

[0039] Recombinant production of the hAC5 polypeptide involves using a nucleic acid sequence that encodes hAC5, as is set forth in FIG. 1, or its degenerate analogs. The nucleic acid can be prepared either by retrieving the native sequence, as described below, or by using substantial portions of the known native sequence as a probe, or it can be synthesized de novo using procedures that are well known in the art.

[0040] The nucleic acid may be ligated into expression vectors suitable for the desired host and then transformed into compatible cells. Suitable vectors suitable for use in transforming bacterial cells are well known in the art. Plasmids and bacteriophages, such as lambda phage, are commonly used as vectors for bacterial hosts such as E. coli. Virus vectors are suitable for use in mammalian and insect cells for expression of exogenous DNA. Mammalian cells are readily transformed with SV40 or polyoma virus; and insect cells in culture may be transformed with baculovirus expression vectors. Suitable yeast vector systems include yeast centromere plasmids, yeast episomal plasmids and yeast integrating plasmids. Alternatively, nucleic acids may be introduced directly into a host cell by techniques such as are well known in the art.

[0041] The cells are cultured under conditions favorable for the expression of the gene encoding the hAC5 polypeptide and cells displaying hAC5 on the surface are then harvested. Suitable eukaryotic host cells include mammalian cells, plant cells, yeast cells and insect cells. Suitable prokaryotic host cells, include bacterial cells such as E. coli and Bacillus subtilis, Chinese Hamster Ovary cells, COS cells, the rat-2 fibroblast cell line, the human embryonic kidney 293 cell line, and insect cell lines such as Sf-9.

[0042] This invention also relates to nucleic acids that encode or are complementary to a hAC5 polypeptide. These nucleic acids can then be used to produce the polypeptide in recombinant cell culture for diagnostic use or for potential therapeutic use. In still other aspects, the invention provides an isolated nucleic acid molecule encoding hAC5, either labeled or unlabeled, or a nucleic acid sequence that is complementary to, or hybridizes under stringent conditions to, a nucleic acid sequence encoding hAC5. The isolated nucleic acid molecule of the invention excludes nucleic acid sequences which encode, or are complementary to nucleic acid sequences encoding, other known adenylyl cyclase isoforms

[0043] This invention also provides a replicable vector comprising a nucleic acid molecule encoding hAC5 operably linked to control sequences recognized by a host transformed by the vector; host cells transformed with the vector; and a method of using a nucleic acid molecule encoding hAC5 to effect the production of hAC5 on the cell surface or as soluble fragments, comprising expressing the nucleic acid molecule in a culture of the transformed host cells and recovered from the cells. The nucleic acid sequence is also useful in hybridization assays for hAC5-encoding nucleic acid molecules.

[0044] In still further embodiments of the invention, a method is described for producing hAC5 comprising inserting into the DNA of a cell containing the nucleic acid sequence encoding hAC5, a transcription modulatory element (such as an enhancer or a silencer) in sufficient proximity and orientation to the hAC5-coding sequence to influence transcription thereof, with an optional further step comprising culturing the cell containing the transcription modulatory element and the hAC5-encoding nucleic acid sequence.

[0045] This invention also covers a cell comprising a nucleic acid sequence encoding the hAC5 polypeptide and an exogenous transcription modulatory element in sufficient proximity and orientation to the above coding sequence to influence transcription thereof and a host cell containing the nucleic acid sequence encoding hAC5 operably linked to exogenous control sequences recognized by the host cell.

[0046] This invention provides a method for obtaining cells having increased or decreased transcription of the nucleic acid molecule encoding the hAC5 polypeptide, comprising: providing cells containing the nucleic acid molecule; introducing into the cells a transcription modulating element; and screening the cells for a cell in which the transcription of the nucleic acid molecule is increased or decreased.

[0047] Human adenylyl cyclase type V nucleic acids for use in the invention can be produced as follows. A hAC5 “nucleic acid” is defined as RNA or DNA that encodes the hAC5 polypeptide, or is complementary to nucleic acid sequence encoding hAC5, or hybridizes to such nucleic acid and remains stably bound to it under stringent conditions, or encodes a polypeptide sharing at least 75% sequence identity, preferably at least 80%, and more preferably at least 85%, with the deduced amino acid sequence shown in FIG. 1. It is typically at least about 10 nucleotides in length and preferably has hAC5 related biological or immunological activity. Specifically contemplated are genomic DNA, cDNA, mRNA and antisense molecules, as well as nucleic acids based on alternative backbone or including alternative bases whether derived from natural sources or synthesized.

[0048] Of particular interest is a hAC5 nucleic acid that encodes a full-length molecule, including but not necessarily the native signal sequence thereof. Nucleic acid encoding full-length protein is obtained by screening selected cDNA or genomic libraries using the deduced amino acid sequence disclosed herein for the first time, and, if necessary, using conventional primer extension procedures to secure DNA that is complete at its 5′ coding end. Such a clone is readily identified by the presence of a start codon in reading frame with the original sequence.

[0049] DNA encoding an amino acid sequence variant of the hAC5 polypeptide is prepared as described below or by a variety of methods known in the art. These methods include, but are not limited to, isolation from a natural source (in the case of naturally occurring amino acid sequence variants) or preparation by oligonucleotide-mediated (or site-directed) mutagenesis, PCR mutagenesis, and cassette mutagenesis of an earlier prepared variant or a non-variant version of hAC5.

[0050] Techniques for isolating and manipulating nucleic acids are disclosed for example by the following documents: U.S. Pat. No. 5,030,576, U.S. Pat. No. 5,030,576 and International Patent Publications WO94/11504 and WO93/03162. See, also, Sambrook, et al., “Molecular Cloning: A Laboratory Manual”, 2nd Edition, Cold Spring Harbor Press, Cold Spring Harbor, N.Y., 1989, and Ausubel, et al. “Current Protocols in Molecular Biology”, Vol. 2, Wiley-Interscience, New York, 1987.

[0051] The isolation, recombinant production and characterization of the hAC5 polypeptide allows for the design of assay systems using hAC5. The availability of the isolated cells providing hAC5 on their surface and the availability of the recombinant DNA encoding hAC5 which permits display and expression of the enzyme on host cell surfaces, all makes such cells available as a valuable tool for evaluating the ability of candidate pharmaceuticals, both agonists and antagonists, to affect the activity of hAC5. In this manner, the invention is related to assay systems which utilize isolated or recombinantly produced hAC5 to screen for agonist and antagonist activity of candidate drugs. This assay is especially useful in assuring that these candidate therapeutic agents have the desired effect on hAC5. Determination of these properties is essential in evaluating the specificity of drugs for other adenylyl cyclase isoforms.

[0052] The host cells are typically animal cells, most typically mammalian cells. In order to be useful in the assays, the cells must have intracellular mechanisms which permit hAC5 to be displayed on the cell surface or to be expressed as soluble fragments. The animal host cells expressing the DNA encoding the hAC5 polypeptide or a fragment thereof are then cultured to effect the expression of the encoding nucleic acids so as to either 1) produce hAC5 display on the cell surface such that the cells can then be used directly in assays for assessment of a candidate drug to bind to or otherwise affect the activity of the enzyme, or 2) produce hAC5 as soluble fragments which can then be purified and reconstituted to obtain an enzymatically active compound useful in screening assays.

[0053] There are several possible strategies to identify compounds which affect hAC5 activity. Over expression of the hAC5 cDNA can provide a means for isolation of large quantities of crude membrane preparations from a stable cell line. HEK-293 cells have been found to be particularly useful for this purpose. In this system the measurable enzyme activity would be predominantly from expression of recombinant hAC5. A highly sensitive, reproducible, high throughput screening system is desirable, with enzyme activity detected in a 96 well, scintillation proximity-type assay to measure product formation (cAMP). There are numerous screening assays that can be utilized. For example, the basal (unstimulated) activity of hAC5 can be measured as a method of detecting both agonists and antagonists of the hAC5 enzyme. In addition, stimulation of the enzyme by its most relevant physiological activator, the heterotrimeric G protein subunit, G_(αs), can be assayed using activated (GTPgS bound) recombinant bovine G_(as) (expressed and purified from bacteria), with the expectation that additional compounds may be identified which inhibit G_(as) stimulation of the hAC5 polypeptide. Other stimulatory agents can also be used, such as forskolin or forskolin analogs. “Hits”, i.e., compounds which affect hAC5, in any of these screens will be further evaluated in other assays to help focus on compounds which are relevant to the targeted isoform.

[0054] Another method of evaluating candidates as potential therapeutic agents typically involves a screening based approach such as a binding assay in which the candidate (such as a peptide or a small organic molecule) would be tested to measure if, or to what extent, it binds the catalytic subunit of the hAC5 enzyme. Preferably, a mammalian cell line that expresses recombinant hAC5 or plasma membrane preparations thereof, will be used in the assay. For example, a candidate antagonist competes for binding to hAC5 with either a labeled agonist or antagonist, for example labeled forskolin or a labeled forskolin analog. Varying concentrations of the candidate are supplied, along with a constant concentration of the labeled agonist or antagonist. The inhibition of binding of the labeled material can then be measured using established techniques. This measurement is then correlated to determine the amount and potency of the candidate that is bound to hAC5.

[0055] Another method of identifying compounds which affect hAC5 activity is the rational design of synthetic compounds based on nucleotide scaffolds, targeted to either of two distinct sites on the hAC5 enzyme. One of these is the active site (ATP being the substrate, cAMP being the product) and the other is the separate P site (adenine nucleoside 3′-polyphosphates reportedly demonstrating the greatest inhibitory activity, with either pure or crude enzyme preparations). As a related approach, one could attempt to design forskolin analogues which may demonstrate isoform specific effects.

[0056] In addition, using the above assays, the ability of a candidate drug to stimulate or inhibit the activity of hAC5 can be tested directly.

[0057] Once lead candidates are identified, and for purposes of demonstrating that isoform specificity may be achieved with small molecule modulators, it is desirable to develop assay systems which monitor most, and preferably all, human adenylyl cyclase isoforms. These assays may be used to evaluate either existing (e.g. forskolin analogs or P site inhibitors) or newly discovered small molecule modulators and determine structure activity relationships for different adenylyl cyclase isoforms. Such assays could also be used to evaluate either specific or selective modulators of other adenylyl targets and with use of a whole cell assay, may provide useful insights for designing bioavailability and addressing biological activity of lead candidates.

[0058] The hAC5 also has utility in assays for the diagnosis of diseases and disorders by detection, in tissue samples, of aberrant expression of the hAC5 enzyme.

[0059] Another aspect of the invention relates to hAC5 agonists that imitate the naturally occurring form of hAC5. These agonists are useful as control reagents in the above-mentioned assays to verify the workability of the assay system. In addition, agonists for hAC5 may exhibit useful effects in vivo in treating disease.

[0060] Another aspect of the invention relates to hAC5 antagonists that are modified forms of hAC5 peptides. Such antagonists bind to hAC5, and prevent enzyme-substrate interaction by blocking their binding to hAC5. Another group of compounds within the scope of the invention, are antagonists of hAC5 substrate, i.e., these are substrate inhibitors. Both these types of antagonists find utility in diminishing or mediating events based upon enzyme-substrate interaction such as cAMP production. Yet another second group of antagonists includes antibodies designed to bind specific portions of hAC5. In general, these are monoclonal antibody preparations which are highly specific for any desired region of hAC5, although polyclonal antibodies are also contemplated by this invention. The antibodies, which are explained in greater detail below, are also useful in immunoassays for the hAC5 enzyme, for example, in assessing successful expression of the gene in recombinant systems.

[0061] In both the agonists and antagonists, a preferred embodiment is that class of compounds having amino acid sequences that are encoded by the hAC5 gene. The invention also includes those compounds where one, two, three or more of said amino acid residues are replaced by one(s) which is not encoded genetically. Also included in the invention are isolated DNA molecules that encode these specific peptides.

[0062] It is believed that the extracellular domains of enzymes may play a key role in extracellular activities, for example, in enzyme regulation. Accordingly, the invention includes agonists and antagonists having amino acid sequences, in whole or in part, corresponding to the extracellular domains of hAC5, the sequences of which can be approximated from the amino acid sequence of FIG. 1 and the hydropathy analysis of FIG. 4. The invention also includes agonists and antagonists that affect the enzyme's function by binding to the N- or C-terminus or to one of the intracellular (ICD) domains of hAC5, the sequences of which can be approximated from the amino acid sequence of FIG. 1 and the hydropathy analysis.

[0063] In other adenylyl cyclases, the ICD IV and carboxy terminus regions have been shown to play a role in enzyme activity or G_(a) or forskolin interaction. See for example: Whisnant, et al., supra. Accordingly, it is expected that the amino acid sequences of the ICD IV and carboxy terminus regions of hAC5, in whole or in part, will be particularly useful in designing antibodies or peptides that can bind the enzyme and block enzyme activity or G_(as) interaction.

[0064] As the understanding of adenylyl cyclases and factors which effect isoform activity increases, rational drug design is becoming a viable alternative in pharmaceutical research. It is believed that the two conserved intracellular domains of adenylyl cyclase (the C₁ and C₂ domains) associate to form an active enzyme. This has been demonstrated with studies that combine both expressed recombinant C₁ and C₂ domains. Both the C₁ and C₂ domains are required to reconstitute enzyme activity while either alone has no substantial activity. Forskolin plus G_(as) stimulates this system, by increasing the association of the two domains. Designing assays which monitor enzyme activity, dependent on association of two separate domains, is expected to provide greater sensitivity to antagonists since this would presumably be more easily disrupted. Other studies have demonstrated that peptides, comprised of sequences from conserved regions of the intracellular domains, act as inhibitors of detergent solubilized enzyme preparations. This invention contemplates the use of peptide walking strategies, to delimit regions of the modulator which may be responsible for its activity, leading to the design of small molecule inhibitors. Finally, knowledge of uncharacterized, physiological modulators of adenylyl cyclase, particularly those that demonstrate isoform specificity, may provide new assay systems for identifying novel AC modulators. It is expected that many of these modulators would be proteins and some may be identified while using adenylyl cyclase sequences as “bait” in a yeast two hybrid system. Alternatively one may identify proteins which coprecipitate with adenylyl cyclase upon capture with adenylyl cyclase antibodies.

[0065] The peptide agonists and antagonists of the invention are preferably about 10-100 amino acids in length, more preferably 25-75 amino acids in length. These peptides can be readily prepared using standard solid phase or solution phase peptide synthesis, as is well known in the art. In addition, the DNA encoding these peptides can be synthesized using commercially available oligonucleotide synthesis instrumentation and recombinantly produced using standard recombinant production systems. Production using solid phase peptide synthesis is required when non-gene encoded amino acids are to be included in the peptide.

[0066] Another aspect of the invention pertains to antibodies, which have both diagnostic and therapeutic uses. Antibodies are able to act as antagonists or agonists by binding specific regions of the hAC5 polypeptide. These antibodies also find utility in immunoassays that measure the presence of hAC5, for example in immunoassays that measure gene expression. In general, antibodies to adenylyl cyclases, and more importantly, those which may recognize specific isoforms of adenylyl cyclase, are a useful tool to evaluate tissue distribution and prevalence of the adenylyl cyclase protein. By identifying regions of dissimilarity between the adenylyl cyclase isoforms and the antigenic potential of these regions, either synthetic peptides or recombinant proteins to these sequences can be created for use in immunization. The resulting antibodies would then be characterized for specificity based on the unique qualities of the immunogen and reactivity with other expressed isoforms. Detection of isoform protein in various tissues can readily be monitored by Westerns blots; however, immunohistochemical analysis would also be useful. This information is useful to identify the adenylyl cyclase target of interest, providing valuable insights into useful therapeutic strategies such as targets in cardiovascular disease, asthma or obesity.

[0067] The antibodies of the present invention can be prepared by techniques that are well known in the art. The antibodies can be monoclonal or polyclonal, but are preferably monoclonal antibodies that are highly specific for hAC5 and can be raised against the whole hAC5 polypeptide or regions thereof. Antibodies are prepared by immunizing suitable mammalian hosts (typically rabbit, rat, mouse, goat, human, etc.) in appropriate immunization protocols using the peptide haptens (immunogen) alone, if they are of sufficient length, or, if desired, or if required to enhance immunogenicity, conjugated to suitable carriers. The immunogen will typically contain a portion of the hAC5 polypeptide that is intended to be targeted by the antibodies. Critical regions include those regions corresponding to the extracellular domains of the hAC5 enzyme, any region(s) of proteolytic cleavage, and any segment(s) of the extracellular segment critical for activation. Methods for preparing immunogenic conjugates with carriers such as bovine serum albumin, keyhole limpet hemocyanin, or other carrier proteins are well known in the art. In some circumstances, direct conjugation using, for example, carbodiinide reagents may be effective; in other instances linking reagents such as those supplied by Pierce Chemical Co., Rockford, Ill., may be desirable to provide accessibility to the hapten. The hapten can be extended at the amino or carboxy terminus with a cysteine residue or interspersed with cysteine residues, for example, to facilitate linking to carrier. The desired immunogen is administered to a host by injection over a suitable period of time using suitable adjuvants followed by collection of sera. Over the course of the immunization schedule, titers of antibodies are taken to determine the adequacy of antibody formation.

[0068] Polyclonal antibodies are suitable for many diagnostic and research purposes and are easily prepared. Monoclonal antibodies are often preferred for therapeutic applications and are prepared by continuous hybrid cell lines and collection of the secreted protein. Immortalized cell lines that secrete the desired monoclonal antibodies can be prepared by the method described in Kohler and Milstein, Nature 256:495-497 (1975) or modifications which effect immortalization of lymphocytes or spleen cells, as is generally known. The immortalized cell lines are then screened by immunoassay techniques in which the antigen is the immunogen or a cell expressing hAC5 on its surface. Cells that are found to secrete the desired antibody, can then be cultured in vitro or by production in the ascites fluid. The antibodies are then recovered from the culture supernatant or from the ascites supernatant.

[0069] Alternately, antibodies can be prepared by recombinant means, i.e., the cloning and expression of nucleotide sequences or mutagenized versions thereof that at a minimum code for the amino acid sequences required for specific binding of natural antibodies. Antibody regions that bind specifically to the desired regions of hAC5 can also be produced as chimeras with regions of multiple species origin.

[0070] Antibodies may include a complete immunoglobulin or a fragment thereof, and includes the various classes and isotypes such as IgA, IgD, IgE, IgG1, IgG2a, IgG2b, IgG3 and IgM. Fragments include Fab, Fv, F(ab′)₂, Fab′, and so forth. Fragments of the monoclonals or the polyclonal antisera which contain the immunologically significant portion can be used as antagonists, as well as the intact antibodies. Use of immunologically reactive fragments, such as the Fab, Fab′, or F(ab′)₂ fragments is often preferable, especially in a therapeutic context, as these fragments have different immunogenicity than the whole immunoglobulin, and do not carry the biological activity of an immunoglobulin constant domain.

[0071] The antibodies thus produced are useful not only as potential agonist or antagonists for the hAC5 polypeptide, filling the role of agonist or antagonist in the assays of the invention, but are also useful in immunoassays for detecting the hAC5 enzyme. As such these antibodies can be coupled to imaging agents for administration to a subject to allow detection of localized antibody to ascertain the under-or over-expression of hAC5 in tissues of interest. In addition, these reagents are useful in vitro to detect, for example, the successful production of hAC5 on the surface of the recombinant host cells.

[0072] Yet another aspect of the invention relates to pharmaceutical compositions containing the compounds and antibodies of the invention. The agonists and antagonists of the invention have therapeutic utility in (1) treating diseases caused by aberrant activity of the hAC5 enzyme in tissues where it is customarily found, for example in the heart and brain and (2) treating diseases whose symptoms can be ameliorated by stimulating or inhibiting the activity of hAC5.

[0073] The peptide agonists and antagonists of the invention can be administered in conventional formulations for systemic administration such as is well known in the art. Typical formulations may be found, for example, in Remington's Pharmaceutical Sciences, Mack Publishing Co., Easton Pa., latest edition.

[0074] Preferred forms of systemic administration include injection, typically by intravenous injection. Other injection routes, such as subcutaneous, intramuscular, or intraperitoneal, can also be used. More recently, alternative means for systemic administration of peptides have been devised which include transmucosal and transdermal administration using penetrants such as bile salts or fusidic acids or other detergents. In addition, if properly formulated in enteric or encapsulated formulations, oral administration may also be possible. Administration of these compounds may also be topical and/or localized, in the form of salves, pastes, gels and the like.

[0075] The dosage range required depends on the choice of peptide, the route of administration, the nature of the formulation, the nature of the patient's condition, and the judgment of the attending physician. Suitable dosage ranges, however, are in the range of 0.1-100 μg/kg of subject. Wide variations in the needed dosage, however, are to be expected in view of the variety of peptides available and the differing efficiencies of various routes of administration. For example, oral administration would be expected to require higher dosages than administration by intravenous injection. Variations in these dosage levels can be adjusted using standard empirical routines for optimization as is well understood in the art.

[0076] The invention also relates to the therapeutic, prophylactic and research uses of various techniques to block or modulate the expression of the hAC5 by interfering with the transcription of translation of a DNA or RNA molecule encoding the hAC5. This includes a method to inhibit or regulate expression of hAC5 in a cell comprising providing to the cell an oligonucleotide molecule which is antisense to, or forms a triple helix with, hAC5-encoding DNA or with DNA regulating expression of hAC5-encoding DNA, in an amount sufficient to inhibit or regulate expression of the hAC5, thereby inhibiting or regulating its expression. Also included is a method to inhibit or regulate expression of hAC5 in a subject, comprising administering to the subject an oligonucleotide molecule which is antisense to, or forms a triple helix with, hAC5-encoding DNA or with DNA regulating expression of hAC5-encoding DNA, in an amount sufficient to inhibit or regulate expression of hAC5 in the subject, thereby inhibiting or regulating its expression. The antisense molecule or triple helix-forming molecule in the above methods is preferably a DNA or RNA oligonucleotide. These utilities are described in greater detail below.

[0077] The constitutive expression of antisense RNA in cells has been shown to inhibit the expression of about 20 different genes in mammals and plants, and the list continually grows (Hambor, et al., J. Exp. Med. 168:1237-1245 (1988); Holt, et al., Proc. Natl. Acad. Sci. 83:4794-4798 (1986); Izant, et al., Cell 36:1007-1015 (1984); Izant, et al., Science 229:345-352 (1985) and De Benedetti, et al., Proc. Natl. Acad. Sci. 84:658-662 (1987)). Possible mechanisms for the antisense effect are the blockage of translation or prevention of splicing, both of which have been observed in vitro. Interference with splicing allows the use of intron sequences (Munroe, EMBO. J. 7:2523-2532 (1988) which should be less conserved and therefore result in greater specificity in inhibiting expression of a protein of one species but not its homologue in another species.

[0078] Therapeutic gene regulation is accomplished using the “antisense” approach, in which the function of a target gene in a cell or organism is blocked, by transfection of DNA, preferably an oligonucleotide, encoding antisense RNA which acts specifically to inhibit expression of the particular target gene. The sequence of the antisense DNA is designed to result in a full or preferably partial antisense RNA transcript which is substantially complementary to a segment of the gene or mRNA which it is intended to inhibit. The complementarity must be sufficient so that the antisense RNA can hybridize to the target gene (or mRNA) and inhibit the target gene's function, regardless of whether the action is at the level of splicing, transcription or translation. The degree of inhibition, readily discernible by one of ordinary skill in the art without undue experimentation, must be sufficient to inhibit, or render the cell incapable of expressing, the target gene. One of ordinary skill in the art will recognize that the antisense RNA approach is but one of a number of known mechanisms which can be employed to block specific gene expression.

[0079] By the term “antisense” is intended an RNA sequence, as well as a DNA sequence coding therefor, which is sufficiently complementary to a particular mRNA molecule for which the antisense RNA is specific to cause molecular hybridization between the antisense RNA and the mRNA such that translation of the mRNA is inhibited. Such hybridization must occur under in vivo conditions, that is, inside the cell. The action of the antisense RNA results in specific inhibition of gene expression in the cell. See Albers, et al., “Molecular Biology Of The Cell”, 2nd Ed., Garland Publishing, Inc., New York, N.Y. (1989), in particular, pages 195-196.

[0080] The antisense RNA of the present invention may be hybridizable to any of several portions of a target mRNA, including the coding sequence, a 3′ or 5′ untranslated region, or other intronic sequences. A preferred antisense RNA is that complementary to hAC5 mRNA. As is readily discernible by one of skill in the art, the minimal amount of homology required by the present invention is that sufficient to result in hybridization to the specific target mRNA and inhibition of its translation or function while not affecting function of other mRNA molecules and the expression of other genes.

[0081] Antisense RNA is delivered to a cell by transformation or transfection with a vector into which has been placed DNA encoding the antisense RNA with the appropriate regulatory sequences, including a promoter, to result in expression of the antisense RNA in a host cell.

[0082] “Triple helix” or “triplex” approaches involve production of synthetic oligonucleotides which bind to the major groove of a duplex DNA to form a colinear triplex. Such triplex formation can regulate and inhibit cellular growth. See, for example, Hogan, et al., U.S. Pat. No. 5, 176,996; Cohen, et al., Sci. Amer, December 1994, p. 76-82; Helene, Anticancer Drug Design 6:569-584 (1991); Maher III, et al., Antisense Res. Devel. 1:227-281 (Fall 1991); and Crook, et al. eds., “Antisense Research and Applications”, CRC Press, 1993; all of which are incorporated herein by reference. It is based in part on the discovery that a DNA oligonucleotide can bind by triplex formation to a duplex DNA target in a gene regulatory region, thereby repressing transcription initiation (Cooney, et. al. Science 241:456 (1988)). The present invention utilizes methods such as those of Hogan et al., supra, to designing oligonucleotides which will bind tightly and specifically to a duplex DNA target comprising part of the hAC5-encoding DNA or a regulatory sequence thereof. Such triplex oligonucleotides can therefore be used as a class of drug molecules to selectively manipulate the expression of this gene.

[0083] Thus the present invention is directed to providing to a cell or administering to a subject a synthetic oligonucleotide in sufficient quantity for cellular uptake and binding to a DNA duplex of the target hAC5-coding DNA sequence or a regulatory sequence thereof, such that the oligonucleotide binds to the DNA duplex to form a colinear triplex. This method is used to inhibit expression of the hAC5 enzyme on cells in vitro or in vivo. Preferably the target sequence is positioned within the DNA domain adjacent to the RNA transcription origin. This method can also be used to inhibit growth of cells which is dependent on expression of this enzyme. The method may also be used to alter the relative amounts or proportions of the hAC5 expressed on cells or tissues by administering such a triplex-forming synthetic oligonucleotide.

[0084] The following examples are intended to illustrate but not to limit the invention.

EXAMPLE 1 Construction and Screening of a Human Heart cDNA Library

[0085] Whole human heart was used as a source of mRNA. The libraries were purchased from a commercial source, Clontech (Catalog No. HL3026a). The libraries were prepared in a lambda gt10 phage with both oligo-dT and random primers. The primary screening of the lambda gt10 library was carried out with gentle washing (less stringent conditions). Prehybridization and hybridization were carried out at standard conditions. A suitable PCR AC fragment was used as a probe.

[0086] The probe was radiolabeled with ³²P-dCTP by the random primer labeling method. After hybridization, the blot was washed under increasingly stringent conditions and then radioautographed. A positive clone was obtained.

[0087] The next step was to ascertain the full length cDNA sequence from the inserts in the clones. All the positive clones from the human heart library were subcloned into a suitable plasmid. After restriction maps were made, they were further subcloned and sequenced with universal primers or synthesized oligomers. The sequence was performed bidirectionally with Sequenase (Tabor, et al., Proc. Acad. Sci. USA 84:4767-4771 (1987).

[0088] Clone were either used on their own, or sequenced and then used to generate PCR primers which were used to acquire additional clones of interest, by the PCR-based RACE (“rapid amplification of cDNA ends”) technique (Frohman, M. A., Methods Enzymol. 218:340-362 (1991)) and human heart mRNA. One clone of particular interest was used as a probe to screen a separate human heart library and several more clones were obtained. Sequencing revealed an open reading frame of 3783 bases reads through to a TGA, a translation termination codon (FIG. 1). Thus, the clone(s) encode a protein of 1261 amino acids. The entire coding portion of the cDNA and its deduced amino acid sequence are shown (FIG. 1) (SEQ ID NO: 1 and 2, respectively).

[0089] One or more fragments from these clones were subcloned into pcDNA3, obtained from Invitrogen. The resulting expression vector, containing the full length cDNA, was given a designation. Samples of this expression vector, inserted into an appropriate E. coli strain designated SURE, were deposited with the American Type Culture Collection, 12301 Parklawn Drive, Rockville, Md. 20852, on ______, 1997 in accordance with the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the Purposes of Patent Procedure and have been accorded accession number ATCC ______.

EXAMPLE 2 Cloning an Expression of the Human Type V Adenylyl Cyclase

[0090] The human type V adenylyl cyclase was produced by cloning and expressing heart type V adenylyl cyclase cDNA in a suitable expression system using recombinant DNA methods, such as are well known in the art.

[0091] Purified plasmid was transfected into HEK-293 cells using electroporation. The cells were grown in an appropriate growth medium then washed. After the addition of trypsin solution, the cells were incubated, harvested and resuspended in the growth media. Purified plasmid was added to an electroporation cuvette. Cells were added to the DNA and the mixture was pulsed. The cell-DNA mixture was then plated into a suitable growth media. The plate was incubated before placing cells on a suitable selective media

[0092] hAC5, having 1261 amino acids, was analyzed for secondary structure by the method of Kyte, et al., J. Mol. Biol. 157:105-132 (1982). The software, GeneWorks; v.2.45; IntelliGenetics, Inc.; Mountain View; Calif. was used to obtain a hydropathy plot, and thereby identify the membrane related structure of this adenylyl cyclase isoform. The method of Kyte, et al., supra, was used with a window size of 5.

[0093] Thirteen peaks appear in the hydropathy plot, not shown, which represent transmembrane spanning regions. Peaks 1-12 represent transmembrane spanning regions. These results suggest that this adenylyl cyclase isoform has a structure of twelve transmembrane spanning regions, as well as a large cytoplasmic loop located in the middle and at the end, which is consistent with the structures of the previously characterized isoforms. In the transmembrane positions, the fifth extracellular loop is the largest (between the ninth and tenth transmembrane spans). The peak designated “−1” corresponds to the N-terminus region. In all other isoforms, the N-terminus is intracellular. The appearance of peak “−1” on the hydropathy plot raises the possibility that the N-terminus of this isoform is extracellular.

EXAMPLE 3 Evaluation of the Human Type V Adenylyl Cyclase

[0094] The biochemical characteristics of hAC9 were determined in a stable expression system using HEK-293 cells. A fragment of the adenylyl cyclase cDNA containing the whole coding sequence was inserted into a suitable plasmid.

[0095] An assay was performed to measure cAMP product formation and it was determined that the hAC5 enzyme expressed by this cDNA was active.

EXAMPLE 4 Tissue Distribution of the Human Type V Adenylyl Cyclase

[0096] In order to determine the tissue distribution of hAC5, Northern blotting was performed using mRNA from various tissues. Messenger RNA was purified using guanidium sodium and oligo-dT columns from various human tissues.

[0097] The blot was pre-hybridized in a suitable solution before the addition of a probe. Hybridization was performed, followed by washing under increasingly stringent conditions. The blot was then autoradiographed.

[0098] The results of the Northern blot analysis indicated that hAC5 is predominantly expressed in heart and brain tissue. The brain shows somewhat less expression that in the heart.

[0099] All references cited and mentioned above, including patents, journal articles and texts, are all incorporated by reference herein, whether expressly incorporated or not.

[0100] Having now fully described this invention, it will be appreciated by those skilled in the art that the same can be performed within a wide range of equivalent parameters, concentrations, and conditions without departing from the spirit and scope of the invention and without undue experimentation.

[0101] While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth as follows in the scope of the appended claims.

1 2 1 4523 DNA human type V adenylyl cyclase CDS (139)..(3921) 1 gctgcagcgc agggccccgg gccgcccccg acgtgtgacc ctagcctggt ccccctgctc 60 ggccgtccgc cctccccttg gagacccccg gcccggcttc cgggggagga ggaaggagac 120 gacgaggccg aggggggg atg tcc ggc tcc aaa agc gtg agc ccc ccg ggc 171 Met Ser Gly Ser Lys Ser Val Ser Pro Pro Gly 1 5 10 tac gcg gcg cag aag act gcg gcg ccg gcg ccc cgg gga ggc ccc gaa 219 Tyr Ala Ala Gln Lys Thr Ala Ala Pro Ala Pro Arg Gly Gly Pro Glu 15 20 25 cac cgc tct gcg tgg ggc gag gcc gat tcc cgc gcg aat ggc tac ccc 267 His Arg Ser Ala Trp Gly Glu Ala Asp Ser Arg Ala Asn Gly Tyr Pro 30 35 40 cat gcc ccc ggg ggt tct gcc cgc ggc tcc acc aag aaa ccc ggg ggg 315 His Ala Pro Gly Gly Ser Ala Arg Gly Ser Thr Lys Lys Pro Gly Gly 45 50 55 gcg gtg acc ccg cag cag cag cag cgc ctg gcc agc cgc tgg cgc agc 363 Ala Val Thr Pro Gln Gln Gln Gln Arg Leu Ala Ser Arg Trp Arg Ser 60 65 70 75 gac gac gac gac gat cct ccg ctg agc ggt gac gac ccc ctg gcc ggg 411 Asp Asp Asp Asp Asp Pro Pro Leu Ser Gly Asp Asp Pro Leu Ala Gly 80 85 90 ggc ttc ggc ttc agc ttc cgc tcc aag tcc gcc tgg cag gag cgc ggc 459 Gly Phe Gly Phe Ser Phe Arg Ser Lys Ser Ala Trp Gln Glu Arg Gly 95 100 105 ggc gac gac tgc ggt cgc ggc agc cgc cgg cag cgg cgg ggc gcg gcc 507 Gly Asp Asp Cys Gly Arg Gly Ser Arg Arg Gln Arg Arg Gly Ala Ala 110 115 120 agc ggg ggc agc acc cgg gcg ccc cct gcg ggc ggc ggc ggc ggc tcg 555 Ser Gly Gly Ser Thr Arg Ala Pro Pro Ala Gly Gly Gly Gly Gly Ser 125 130 135 gcg gcg gcg gct gcc tcg gcg ggc ggg acg gag gtg cgc cct cgc tcg 603 Ala Ala Ala Ala Ala Ser Ala Gly Gly Thr Glu Val Arg Pro Arg Ser 140 145 150 155 gtg gag gtg ggt ctg gag gag cgg cgg ggc aag ggg cgc gcg gcc gac 651 Val Glu Val Gly Leu Glu Glu Arg Arg Gly Lys Gly Arg Ala Ala Asp 160 165 170 gag ctg gag gcc ggc gcc gtc gag ggc ggc gag ggg tcc ggg gat ggc 699 Glu Leu Glu Ala Gly Ala Val Glu Gly Gly Glu Gly Ser Gly Asp Gly 175 180 185 ggc agc tcg gcg gac tcg ggc tcg ggc gcg ggg ccc ggc gcg gtg ctg 747 Gly Ser Ser Ala Asp Ser Gly Ser Gly Ala Gly Pro Gly Ala Val Leu 190 195 200 tcc ctg ggc gcc tgc tgc ctg gcg ttg ctg cag ata ttc cgc tcc aag 795 Ser Leu Gly Ala Cys Cys Leu Ala Leu Leu Gln Ile Phe Arg Ser Lys 205 210 215 aag ttc ccg tcg gac aaa ctg gag cgg ctg tac cag cgc tac ttc ttc 843 Lys Phe Pro Ser Asp Lys Leu Glu Arg Leu Tyr Gln Arg Tyr Phe Phe 220 225 230 235 cgc ctg aac cag agc agc ctc acc atg ctc atg gcc gtg ctg gtg ctc 891 Arg Leu Asn Gln Ser Ser Leu Thr Met Leu Met Ala Val Leu Val Leu 240 245 250 gtg tgc ctg gtc atg ttg gcc ttc cac gcg gcg cgg ccc ccg ctc cag 939 Val Cys Leu Val Met Leu Ala Phe His Ala Ala Arg Pro Pro Leu Gln 255 260 265 ctg ccc tac ctg gcc gtg ctg gcg gcc gcc gtc ggc gtg atc ctc atc 987 Leu Pro Tyr Leu Ala Val Leu Ala Ala Ala Val Gly Val Ile Leu Ile 270 275 280 atg gct gtg ctt tgc aac cgc gcc gcc ttc cac cag gac cac atg ggc 1035 Met Ala Val Leu Cys Asn Arg Ala Ala Phe His Gln Asp His Met Gly 285 290 295 ctg gcc tgc tat gcg ctc atc gcc gtg gtg ctg gcc gtc cag gtg gtg 1083 Leu Ala Cys Tyr Ala Leu Ile Ala Val Val Leu Ala Val Gln Val Val 300 305 310 315 ggc ctg ctg ctg ccg cag cca cgc agc gcc tct gag ggc atc tgg tgg 1131 Gly Leu Leu Leu Pro Gln Pro Arg Ser Ala Ser Glu Gly Ile Trp Trp 320 325 330 acc gtg ttc ttc atc tac acc atc tac acg ctg ctg ccc gtg cgc atg 1179 Thr Val Phe Phe Ile Tyr Thr Ile Tyr Thr Leu Leu Pro Val Arg Met 335 340 345 cgg gcc gca gtg ctc agc ggg gtg ctc ctg tcc gcc ctc cac ctg gcc 1227 Arg Ala Ala Val Leu Ser Gly Val Leu Leu Ser Ala Leu His Leu Ala 350 355 360 atc gcc ctg cgc acc aac gcc cag gac cag ttc ctg ctg aag cag ctt 1275 Ile Ala Leu Arg Thr Asn Ala Gln Asp Gln Phe Leu Leu Lys Gln Leu 365 370 375 gtc tcc aat gtt ctc att ttc tcc tgc acc aac atc gtg ggt gtc tgc 1323 Val Ser Asn Val Leu Ile Phe Ser Cys Thr Asn Ile Val Gly Val Cys 380 385 390 395 acc cac tat ccg gct gag gtc tcc cag aga cag gct ttc cag gag acc 1371 Thr His Tyr Pro Ala Glu Val Ser Gln Arg Gln Ala Phe Gln Glu Thr 400 405 410 cga gag tgc atc cag gcg cgg ctc cac tcg cag cgg gag aac cag cag 1419 Arg Glu Cys Ile Gln Ala Arg Leu His Ser Gln Arg Glu Asn Gln Gln 415 420 425 cag gaa cgg ctc ctg ctg tct gtc ctt ccc cgt cat gtt gcc atg gag 1467 Gln Glu Arg Leu Leu Leu Ser Val Leu Pro Arg His Val Ala Met Glu 430 435 440 atg aaa gca gac atc aac gcc aag cag gag gat atg atg ttc cat aag 1515 Met Lys Ala Asp Ile Asn Ala Lys Gln Glu Asp Met Met Phe His Lys 445 450 455 att tac atc cag aaa cat gac aac gtg agc atc ctg ttt gct gac atc 1563 Ile Tyr Ile Gln Lys His Asp Asn Val Ser Ile Leu Phe Ala Asp Ile 460 465 470 475 gag ggc ttc acc agc ctg gcg tcc cag tgc act gca cag gaa ctg gtc 1611 Glu Gly Phe Thr Ser Leu Ala Ser Gln Cys Thr Ala Gln Glu Leu Val 480 485 490 atg acc ctc aac gag ctc ttc gcc cgc ttt gac aag ctg gcc gca gag 1659 Met Thr Leu Asn Glu Leu Phe Ala Arg Phe Asp Lys Leu Ala Ala Glu 495 500 505 aat cac tgt tta cgt att aag atc ctt ggg gat tgt tat tac tgc gtc 1707 Asn His Cys Leu Arg Ile Lys Ile Leu Gly Asp Cys Tyr Tyr Cys Val 510 515 520 tcg ggg ctg cct gaa gca agg gct gac cac gcc cac tgc tgt gtg gag 1755 Ser Gly Leu Pro Glu Ala Arg Ala Asp His Ala His Cys Cys Val Glu 525 530 535 atg ggc atg gac atg atc gag gcc atc tcg ttg gtc cgg gag gtg aca 1803 Met Gly Met Asp Met Ile Glu Ala Ile Ser Leu Val Arg Glu Val Thr 540 545 550 555 ggg gtg aac gtg aac atg cgt gtg gga att cac agc ggg cga gta cac 1851 Gly Val Asn Val Asn Met Arg Val Gly Ile His Ser Gly Arg Val His 560 565 570 tgc ggt gtc ctt ggt ctc agg aag tgg cag ttc gac gtc tgg tct aac 1899 Cys Gly Val Leu Gly Leu Arg Lys Trp Gln Phe Asp Val Trp Ser Asn 575 580 585 gat gtc acg cta gcc aac cac atg gag gct ggc ggc aag gca gga cgc 1947 Asp Val Thr Leu Ala Asn His Met Glu Ala Gly Gly Lys Ala Gly Arg 590 595 600 atc cac atc acc aag gct aca ctc aac tac ctg aat ggg gac tac gag 1995 Ile His Ile Thr Lys Ala Thr Leu Asn Tyr Leu Asn Gly Asp Tyr Glu 605 610 615 gtg gag cca ggc tgt ggg ggc gag cgc aac gcc tac ctc aag gag cac 2043 Val Glu Pro Gly Cys Gly Gly Glu Arg Asn Ala Tyr Leu Lys Glu His 620 625 630 635 agt atc gag acc ttc ctc atc ctg cgc tgc acc cag aag cgg aaa gaa 2091 Ser Ile Glu Thr Phe Leu Ile Leu Arg Cys Thr Gln Lys Arg Lys Glu 640 645 650 gag aag gcc atg atc gcc aag atg aac cgc cag aga acc aac tcc atc 2139 Glu Lys Ala Met Ile Ala Lys Met Asn Arg Gln Arg Thr Asn Ser Ile 655 660 665 ggg cac aac cca cca cac tgg ggg gct gag cgc ccc ttc tac aac cac 2187 Gly His Asn Pro Pro His Trp Gly Ala Glu Arg Pro Phe Tyr Asn His 670 675 680 ctg ggt ggc aac cag gtg tcc aag gag atg aag cgg atg ggc ttt gaa 2235 Leu Gly Gly Asn Gln Val Ser Lys Glu Met Lys Arg Met Gly Phe Glu 685 690 695 gac ccc aag gac aag aac gcc cag gag agt gcg aac cct gag gat gaa 2283 Asp Pro Lys Asp Lys Asn Ala Gln Glu Ser Ala Asn Pro Glu Asp Glu 700 705 710 715 gtg gat gag ttt ctg ggc cgt gcc att gac gcc agg agc att gat agg 2331 Val Asp Glu Phe Leu Gly Arg Ala Ile Asp Ala Arg Ser Ile Asp Arg 720 725 730 ctt cgg tct gag cac gtc cgc aag ttc ctc ctg acc ttc agg gag cct 2379 Leu Arg Ser Glu His Val Arg Lys Phe Leu Leu Thr Phe Arg Glu Pro 735 740 745 gac tta gag aag aag tac tcc aag cag gta gac gac cga ttt ggt gcc 2427 Asp Leu Glu Lys Lys Tyr Ser Lys Gln Val Asp Asp Arg Phe Gly Ala 750 755 760 tat gtg gcg tgt gcc tcg ctc gtc ttc ctc ttc atc tgc ttt gtc cag 2475 Tyr Val Ala Cys Ala Ser Leu Val Phe Leu Phe Ile Cys Phe Val Gln 765 770 775 atc acc atc gtg ccc cac tcc ata ttc atg ctc agc ttc tac ctg acc 2523 Ile Thr Ile Val Pro His Ser Ile Phe Met Leu Ser Phe Tyr Leu Thr 780 785 790 795 tgt tcc ctg ctg ctg acc ttg gtg gtg ttt gtg tct gtg atc tac tcc 2571 Cys Ser Leu Leu Leu Thr Leu Val Val Phe Val Ser Val Ile Tyr Ser 800 805 810 tgc gta aag ctc ttc ccc tcc cca ctg cag acc ctc tcc agg aag atc 2619 Cys Val Lys Leu Phe Pro Ser Pro Leu Gln Thr Leu Ser Arg Lys Ile 815 820 825 gtg cgg tcc aag atg aac agc acc ctg gtt ggg gtg ttc acc atc acc 2667 Val Arg Ser Lys Met Asn Ser Thr Leu Val Gly Val Phe Thr Ile Thr 830 835 840 ctg gtg ttc ctg gcg gct ttt gtc aac atg ttc acg tgc aac tcc agg 2715 Leu Val Phe Leu Ala Ala Phe Val Asn Met Phe Thr Cys Asn Ser Arg 845 850 855 gac ctg ctg ggc tgc ttg gca cag gag cac aac atc agc gcg agc cag 2763 Asp Leu Leu Gly Cys Leu Ala Gln Glu His Asn Ile Ser Ala Ser Gln 860 865 870 875 gtc aac gcg tgt cac gtg gcg gag tcg gcc gtc aac tac agc ctg ggc 2811 Val Asn Ala Cys His Val Ala Glu Ser Ala Val Asn Tyr Ser Leu Gly 880 885 890 gat gag cag ggc ttc tgt ggc agc ccc tgg ccc aac tgc aac ttc ccc 2859 Asp Glu Gln Gly Phe Cys Gly Ser Pro Trp Pro Asn Cys Asn Phe Pro 895 900 905 gag tac ttc acc tac agc gtg ctg ctc agc ctg ctg gcc tgc tcc gtg 2907 Glu Tyr Phe Thr Tyr Ser Val Leu Leu Ser Leu Leu Ala Cys Ser Val 910 915 920 ttc ctg cag atc agc tgc atc ggg aag ctg gtg ctc atg ctg gcc atc 2955 Phe Leu Gln Ile Ser Cys Ile Gly Lys Leu Val Leu Met Leu Ala Ile 925 930 935 gag ctc atc tac gtg ctc atc gtg gag gtg cca ggt gtc acg ctc ttc 3003 Glu Leu Ile Tyr Val Leu Ile Val Glu Val Pro Gly Val Thr Leu Phe 940 945 950 955 gac aac gcc gac ctg ctg gtc acc gcc aac gcc ata gac ttc ttc aac 3051 Asp Asn Ala Asp Leu Leu Val Thr Ala Asn Ala Ile Asp Phe Phe Asn 960 965 970 aac ggg acc tcc cag tgc cct gag cat gca acc aag gtg gca ttg aag 3099 Asn Gly Thr Ser Gln Cys Pro Glu His Ala Thr Lys Val Ala Leu Lys 975 980 985 gtg gtg acg ccc atc atc atc tca gtc ttt gtg ctg gcc ctg tac ctg 3147 Val Val Thr Pro Ile Ile Ile Ser Val Phe Val Leu Ala Leu Tyr Leu 990 995 1000 cac gcc cag cag gtg gag tcc act gcc cgc ctc gac ttc ctc tgg aaa 3195 His Ala Gln Gln Val Glu Ser Thr Ala Arg Leu Asp Phe Leu Trp Lys 1005 1010 1015 ctg cag gcc aca gag gag aaa gag gag atg gag gag ctg cag gcc tac 3243 Leu Gln Ala Thr Glu Glu Lys Glu Glu Met Glu Glu Leu Gln Ala Tyr 1020 1025 1030 1035 aac cgg cgg ctg ctg cac aac atc ctg ccc aag gac gtg gcc gct cac 3291 Asn Arg Arg Leu Leu His Asn Ile Leu Pro Lys Asp Val Ala Ala His 1040 1045 1050 ttc ctg gcc cgc gag cgg cgc aat gat gag ctc tac tat cag tcc tgt 3339 Phe Leu Ala Arg Glu Arg Arg Asn Asp Glu Leu Tyr Tyr Gln Ser Cys 1055 1060 1065 gag tgt gtg gcg gtc atg ttc gcc tcc atc gcc aac ttc tcc gag ttc 3387 Glu Cys Val Ala Val Met Phe Ala Ser Ile Ala Asn Phe Ser Glu Phe 1070 1075 1080 tac gtt gag ctg gag gcc aac aac gag ggt gtc gag tgc ctg cgg cta 3435 Tyr Val Glu Leu Glu Ala Asn Asn Glu Gly Val Glu Cys Leu Arg Leu 1085 1090 1095 ctc aat gag atc atc gct gac ttt gat gag atc atc agc gag gat cgg 3483 Leu Asn Glu Ile Ile Ala Asp Phe Asp Glu Ile Ile Ser Glu Asp Arg 1100 1105 1110 1115 ttc cgg cag ctg gag aag atc aag acc atc ggc agc acc tac atg gct 3531 Phe Arg Gln Leu Glu Lys Ile Lys Thr Ile Gly Ser Thr Tyr Met Ala 1120 1125 1130 gcc tcc ggc ctc aac gac tct acc tac gac aag gtg ggc aag acc cac 3579 Ala Ser Gly Leu Asn Asp Ser Thr Tyr Asp Lys Val Gly Lys Thr His 1135 1140 1145 atc aag gca ctg gcc gac ttt gcc atg aag ctg atg gac cag atg aag 3627 Ile Lys Ala Leu Ala Asp Phe Ala Met Lys Leu Met Asp Gln Met Lys 1150 1155 1160 tac atc aat gag cac tcc ttc aac aac ttc cag atg aag atc ggg ctc 3675 Tyr Ile Asn Glu His Ser Phe Asn Asn Phe Gln Met Lys Ile Gly Leu 1165 1170 1175 aac atc ggc ccc gtg gtg gcc ggg gtg ata ggg gca cga aag cct cag 3723 Asn Ile Gly Pro Val Val Ala Gly Val Ile Gly Ala Arg Lys Pro Gln 1180 1185 1190 1195 tac gac atc tgg ggc aat acc gtg aac gtg gcc agc cgc atg gac agc 3771 Tyr Asp Ile Trp Gly Asn Thr Val Asn Val Ala Ser Arg Met Asp Ser 1200 1205 1210 acc ggt gta ccc gac cgc atc cag gtc acc aca gac atg tac cag gtg 3819 Thr Gly Val Pro Asp Arg Ile Gln Val Thr Thr Asp Met Tyr Gln Val 1215 1220 1225 ctg gct gcc aac acg tac cag ctg gag tgc cgg ggc gtg gtc aag gtc 3867 Leu Ala Ala Asn Thr Tyr Gln Leu Glu Cys Arg Gly Val Val Lys Val 1230 1235 1240 aag ggc aaa ggc gag atg atg acc tac ttc ctc aat gga ggg ccc ccg 3915 Lys Gly Lys Gly Glu Met Met Thr Tyr Phe Leu Asn Gly Gly Pro Pro 1245 1250 1255 ctc agt tagcagctgt tggccaatgg tgccaggcag cctggcctcc agaggcatgg 3971 Leu Ser 1260 aagcagcttc tctgtgtgcc gggggtggcg gggaagccat gctccagccc gcagggctgc 4031 gctgctgaga ttttccactt ggactccaga gcagcttctg cctttgctgg tgggcagcgg 4091 cctctgtccc aggccccggg gtgccagcgt cctgcgagca cccagctgac caaagatgtt 4151 tccctctgta gaagactctg ctagactggg tctgaagctt gagttttcta acaggtgctg 4211 ctgcacaggt ggaaaggagc cgtgggaatg tgtgtgtggc acggcccaga caagggcagg 4271 gctgaggggc ctccgactca gctgggggta gacgggctcg aatgtggcct gggagagcct 4331 agggggcccc aggggtctgc ttttctatgt gagcctttaa acttcagaca ggccaccacc 4391 ctgcacctgc aggggctttg gcacaggagt gctggctttg gagggactgt ggccttcatc 4451 gtggtcctct gcccacacct ccacgcacac agacagtgcc ctaggaggga aacagaacta 4511 attacgaggg gg 4523 2 1261 PRT human type V adenylyl cyclase 2 Met Ser Gly Ser Lys Ser Val Ser Pro Pro Gly Tyr Ala Ala Gln Lys 1 5 10 15 Thr Ala Ala Pro Ala Pro Arg Gly Gly Pro Glu His Arg Ser Ala Trp 20 25 30 Gly Glu Ala Asp Ser Arg Ala Asn Gly Tyr Pro His Ala Pro Gly Gly 35 40 45 Ser Ala Arg Gly Ser Thr Lys Lys Pro Gly Gly Ala Val Thr Pro Gln 50 55 60 Gln Gln Gln Arg Leu Ala Ser Arg Trp Arg Ser Asp Asp Asp Asp Asp 65 70 75 80 Pro Pro Leu Ser Gly Asp Asp Pro Leu Ala Gly Gly Phe Gly Phe Ser 85 90 95 Phe Arg Ser Lys Ser Ala Trp Gln Glu Arg Gly Gly Asp Asp Cys Gly 100 105 110 Arg Gly Ser Arg Arg Gln Arg Arg Gly Ala Ala Ser Gly Gly Ser Thr 115 120 125 Arg Ala Pro Pro Ala Gly Gly Gly Gly Gly Ser Ala Ala Ala Ala Ala 130 135 140 Ser Ala Gly Gly Thr Glu Val Arg Pro Arg Ser Val Glu Val Gly Leu 145 150 155 160 Glu Glu Arg Arg Gly Lys Gly Arg Ala Ala Asp Glu Leu Glu Ala Gly 165 170 175 Ala Val Glu Gly Gly Glu Gly Ser Gly Asp Gly Gly Ser Ser Ala Asp 180 185 190 Ser Gly Ser Gly Ala Gly Pro Gly Ala Val Leu Ser Leu Gly Ala Cys 195 200 205 Cys Leu Ala Leu Leu Gln Ile Phe Arg Ser Lys Lys Phe Pro Ser Asp 210 215 220 Lys Leu Glu Arg Leu Tyr Gln Arg Tyr Phe Phe Arg Leu Asn Gln Ser 225 230 235 240 Ser Leu Thr Met Leu Met Ala Val Leu Val Leu Val Cys Leu Val Met 245 250 255 Leu Ala Phe His Ala Ala Arg Pro Pro Leu Gln Leu Pro Tyr Leu Ala 260 265 270 Val Leu Ala Ala Ala Val Gly Val Ile Leu Ile Met Ala Val Leu Cys 275 280 285 Asn Arg Ala Ala Phe His Gln Asp His Met Gly Leu Ala Cys Tyr Ala 290 295 300 Leu Ile Ala Val Val Leu Ala Val Gln Val Val Gly Leu Leu Leu Pro 305 310 315 320 Gln Pro Arg Ser Ala Ser Glu Gly Ile Trp Trp Thr Val Phe Phe Ile 325 330 335 Tyr Thr Ile Tyr Thr Leu Leu Pro Val Arg Met Arg Ala Ala Val Leu 340 345 350 Ser Gly Val Leu Leu Ser Ala Leu His Leu Ala Ile Ala Leu Arg Thr 355 360 365 Asn Ala Gln Asp Gln Phe Leu Leu Lys Gln Leu Val Ser Asn Val Leu 370 375 380 Ile Phe Ser Cys Thr Asn Ile Val Gly Val Cys Thr His Tyr Pro Ala 385 390 395 400 Glu Val Ser Gln Arg Gln Ala Phe Gln Glu Thr Arg Glu Cys Ile Gln 405 410 415 Ala Arg Leu His Ser Gln Arg Glu Asn Gln Gln Gln Glu Arg Leu Leu 420 425 430 Leu Ser Val Leu Pro Arg His Val Ala Met Glu Met Lys Ala Asp Ile 435 440 445 Asn Ala Lys Gln Glu Asp Met Met Phe His Lys Ile Tyr Ile Gln Lys 450 455 460 His Asp Asn Val Ser Ile Leu Phe Ala Asp Ile Glu Gly Phe Thr Ser 465 470 475 480 Leu Ala Ser Gln Cys Thr Ala Gln Glu Leu Val Met Thr Leu Asn Glu 485 490 495 Leu Phe Ala Arg Phe Asp Lys Leu Ala Ala Glu Asn His Cys Leu Arg 500 505 510 Ile Lys Ile Leu Gly Asp Cys Tyr Tyr Cys Val Ser Gly Leu Pro Glu 515 520 525 Ala Arg Ala Asp His Ala His Cys Cys Val Glu Met Gly Met Asp Met 530 535 540 Ile Glu Ala Ile Ser Leu Val Arg Glu Val Thr Gly Val Asn Val Asn 545 550 555 560 Met Arg Val Gly Ile His Ser Gly Arg Val His Cys Gly Val Leu Gly 565 570 575 Leu Arg Lys Trp Gln Phe Asp Val Trp Ser Asn Asp Val Thr Leu Ala 580 585 590 Asn His Met Glu Ala Gly Gly Lys Ala Gly Arg Ile His Ile Thr Lys 595 600 605 Ala Thr Leu Asn Tyr Leu Asn Gly Asp Tyr Glu Val Glu Pro Gly Cys 610 615 620 Gly Gly Glu Arg Asn Ala Tyr Leu Lys Glu His Ser Ile Glu Thr Phe 625 630 635 640 Leu Ile Leu Arg Cys Thr Gln Lys Arg Lys Glu Glu Lys Ala Met Ile 645 650 655 Ala Lys Met Asn Arg Gln Arg Thr Asn Ser Ile Gly His Asn Pro Pro 660 665 670 His Trp Gly Ala Glu Arg Pro Phe Tyr Asn His Leu Gly Gly Asn Gln 675 680 685 Val Ser Lys Glu Met Lys Arg Met Gly Phe Glu Asp Pro Lys Asp Lys 690 695 700 Asn Ala Gln Glu Ser Ala Asn Pro Glu Asp Glu Val Asp Glu Phe Leu 705 710 715 720 Gly Arg Ala Ile Asp Ala Arg Ser Ile Asp Arg Leu Arg Ser Glu His 725 730 735 Val Arg Lys Phe Leu Leu Thr Phe Arg Glu Pro Asp Leu Glu Lys Lys 740 745 750 Tyr Ser Lys Gln Val Asp Asp Arg Phe Gly Ala Tyr Val Ala Cys Ala 755 760 765 Ser Leu Val Phe Leu Phe Ile Cys Phe Val Gln Ile Thr Ile Val Pro 770 775 780 His Ser Ile Phe Met Leu Ser Phe Tyr Leu Thr Cys Ser Leu Leu Leu 785 790 795 800 Thr Leu Val Val Phe Val Ser Val Ile Tyr Ser Cys Val Lys Leu Phe 805 810 815 Pro Ser Pro Leu Gln Thr Leu Ser Arg Lys Ile Val Arg Ser Lys Met 820 825 830 Asn Ser Thr Leu Val Gly Val Phe Thr Ile Thr Leu Val Phe Leu Ala 835 840 845 Ala Phe Val Asn Met Phe Thr Cys Asn Ser Arg Asp Leu Leu Gly Cys 850 855 860 Leu Ala Gln Glu His Asn Ile Ser Ala Ser Gln Val Asn Ala Cys His 865 870 875 880 Val Ala Glu Ser Ala Val Asn Tyr Ser Leu Gly Asp Glu Gln Gly Phe 885 890 895 Cys Gly Ser Pro Trp Pro Asn Cys Asn Phe Pro Glu Tyr Phe Thr Tyr 900 905 910 Ser Val Leu Leu Ser Leu Leu Ala Cys Ser Val Phe Leu Gln Ile Ser 915 920 925 Cys Ile Gly Lys Leu Val Leu Met Leu Ala Ile Glu Leu Ile Tyr Val 930 935 940 Leu Ile Val Glu Val Pro Gly Val Thr Leu Phe Asp Asn Ala Asp Leu 945 950 955 960 Leu Val Thr Ala Asn Ala Ile Asp Phe Phe Asn Asn Gly Thr Ser Gln 965 970 975 Cys Pro Glu His Ala Thr Lys Val Ala Leu Lys Val Val Thr Pro Ile 980 985 990 Ile Ile Ser Val Phe Val Leu Ala Leu Tyr Leu His Ala Gln Gln Val 995 1000 1005 Glu Ser Thr Ala Arg Leu Asp Phe Leu Trp Lys Leu Gln Ala Thr Glu 1010 1015 1020 Glu Lys Glu Glu Met Glu Glu Leu Gln Ala Tyr Asn Arg Arg Leu Leu 1025 1030 1035 1040 His Asn Ile Leu Pro Lys Asp Val Ala Ala His Phe Leu Ala Arg Glu 1045 1050 1055 Arg Arg Asn Asp Glu Leu Tyr Tyr Gln Ser Cys Glu Cys Val Ala Val 1060 1065 1070 Met Phe Ala Ser Ile Ala Asn Phe Ser Glu Phe Tyr Val Glu Leu Glu 1075 1080 1085 Ala Asn Asn Glu Gly Val Glu Cys Leu Arg Leu Leu Asn Glu Ile Ile 1090 1095 1100 Ala Asp Phe Asp Glu Ile Ile Ser Glu Asp Arg Phe Arg Gln Leu Glu 1105 1110 1115 1120 Lys Ile Lys Thr Ile Gly Ser Thr Tyr Met Ala Ala Ser Gly Leu Asn 1125 1130 1135 Asp Ser Thr Tyr Asp Lys Val Gly Lys Thr His Ile Lys Ala Leu Ala 1140 1145 1150 Asp Phe Ala Met Lys Leu Met Asp Gln Met Lys Tyr Ile Asn Glu His 1155 1160 1165 Ser Phe Asn Asn Phe Gln Met Lys Ile Gly Leu Asn Ile Gly Pro Val 1170 1175 1180 Val Ala Gly Val Ile Gly Ala Arg Lys Pro Gln Tyr Asp Ile Trp Gly 1185 1190 1195 1200 Asn Thr Val Asn Val Ala Ser Arg Met Asp Ser Thr Gly Val Pro Asp 1205 1210 1215 Arg Ile Gln Val Thr Thr Asp Met Tyr Gln Val Leu Ala Ala Asn Thr 1220 1225 1230 Tyr Gln Leu Glu Cys Arg Gly Val Val Lys Val Lys Gly Lys Gly Glu 1235 1240 1245 Met Met Thr Tyr Phe Leu Asn Gly Gly Pro Pro Leu Ser 1250 1255 1260 

1-7. (Canceled).
 8. A method for identifying a candidate compound which binds to a polypeptide selected from the group consisting of: a) a polypeptide which is at least 95% identical to the amino acid sequence of SEQ ID NO:2; b) a polypeptide which is at least 95% identical to the amino acid sequence encoded by the cDNA insert of the plasmid deposited with ATCC as Patent Deposit Number PTA-4115; and c) a polypeptide encoded by a nucleic acid molecule comprising a nucleotide sequence which is at least 95% identical to the nucleotide sequence of SEQ ID NO:1; wherein the polypeptide has adenylyl cyclase activity; the method comprising: i) contacting a sample comprising the polypeptide with a test compound under conditions suitable for binding; and ii) detecting binding of the test compound to the polypeptide; thereby identifying a compound which binds to the polypeptide.
 9. The method of claim 8, wherein the sample is an isolated polypeptide, a membrane-bound form of an isolated polypeptide or a cell comprising the polypeptide.
 10. The method of claim 9, wherein the cell is a mammalian cell.
 11. The method of claim 8, wherein the binding of the test compound to the polypeptide is detected by a method selected from the group consisting of: a) direct detection of test compound/polypeptide binding; b) a competition binding assay; and c) an immunoassay.
 12. The method of claim 8, wherein the binding of the test compound to the polypeptide is detected is by an assay for an activity of the polypeptide.
 13. The method of claim 12, wherein the assay for activity is selected from the group consisting of: a) an assay for measuring adenylyl cyclase activity; and b) an assay for measuring the synthesis of cAMP.
 14. A method for identifying a candidate compound which binds to a polypeptide selected from the group consisting of: a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2; b) a polypeptide comprising the amino acid sequence encoded by the cDNA insert of the plasmid deposited with ATCC as Patent Deposit Number PTA-4115; and c) a polypeptide encoded by the nucleotide sequence set forth in SEQ ID NO: 1; the method comprising: i) contacting a sample comprising the polypeptide with a test compound under conditions suitable for binding; and ii) detecting binding of the test compound to the polypeptide; thereby identifying a compound which binds to the polypeptide.
 15. The method of claim 14, wherein the sample is an isolated polypeptide, a membrane-bound form of an isolated polypeptide or a cell comprising the polypeptide.
 16. The method of claim 15, wherein the cell is a mammalian cell.
 17. The method of claim 14, wherein the binding of the test compound to the polypeptide is detected by a method selected from the group consisting of: a) direct detection of test compound/polypeptide binding; b) a competition binding assay; and c) an immunoassay.
 18. The method of claim 14, wherein the binding of the test compound to the polypeptide is detected is by an assay for an activity of the polypeptide.
 19. The method of claim 18, wherein the assay for activity is selected from the group consisting of: a) an assay for measuring adenylyl cyclase activity; and b) an assay for measuring the synthesis of cAMP.
 20. A method for identifying a candidate compound which binds to a polypeptide selected from the group consisting of: a) a polypeptide comprising a fragment of at least 15 contiguous amino acids of SEQ ID NO:2; b) a polypeptide comprising a fragment of at least 15 contiguous amino acids of the amino acid sequence encoded by the cDNA insert of the plasmid deposited with ATCC as Patent Deposit Number PTA-4115; and c) a polypeptide comprising a fragment of at least 15 contiguous amino acids encoded by the nucleotide sequence set forth in SEQ ID NO:1; wherein the polypeptide has adenylyl cyclase activity; the method comprising: i) contacting a sample comprising the polypeptide with a test compound under conditions suitable for binding; and ii) detecting binding of the test compound to the polypeptide; thereby identifying a compound which binds to the polypeptide.
 21. The method of claim 20, wherein the sample is an isolated polypeptide, a membrane-bound form of an isolated polypeptide or a cell comprising the polypeptide.
 22. The method of claim 21, wherein the cell is a mammalian cell.
 23. The method of claim 20, wherein the binding of the test compound to the polypeptide is detected by a method selected from the group consisting of: a) direct detection of test compound/polypeptide binding; b) a competition binding assay; and c) an immunoassay.
 24. The method of claim 20, wherein the binding of the test compound to the polypeptide is detected is by an assay for an activity of the polypeptide.
 25. The method of claim 24, wherein the assay for activity is selected from the group consisting of: a) an assay for measuring adenylyl cyclase activity; and b) an assay for measuring the synthesis of cAMP. 